Preparation of detergents



the material.

Patented Oct. 24, 1944 PREPARATION OF DETERGENTS George Burt Bradshaw, Wilmington, Del., and

Walter C. Meuly, New Brunswick, N. J., assignors to E. I. du Pont de Nemours & Company, Wilmington, Del., a corporation of Delaware N Drawing. Application November 26, 1941,

Serial No. 420,590

15 Claims.

This invention relates to methods forthe preparation of soaps and soap compositions. More particularly it relates to a novel process of making soaps from glycerides. Still more particularly it relates to a process of making soap from the glycerides of higher open chain aliphatic carboxylic acids. In one of its aspects it relates to an improved method of producing dry soap and/or controlling the water content thereof. It further relates to novel spraying procedures for obtaining sponge-like small particles of soap. The invention also pertains to the separation of glycerine from natural glycerides to produce a refined base. This invention also relates to oil or fat refining and to saponifying methods amenable to continuous processes and to such continuous processes and to novel improvements in the soap making arts.

In the usual process for manufacturing soap naturally occurring oils and fats are first refined or purified and then saponified. In common refining processes caustic soda is added to crude liquid fat so that free fatty acids in the fat are precipitated as soaps. During precipitation, coloring matter, mucilagenous and protein material is precipitated along with the soap. There are many disadvantages connected with this procedure among which are (1) waste of fats since the foots obtained are difficult to utilize and (2) the reactions are slow and tie up processing equipment for long periods of time. In the usual process for manufacture of soap from the refined fats or oils these materials are treated step-wise with dilute caustic soda or potash solutions and then with salt solutions to effect (a) separation of the glycerine, (b) conversion of the fatty material to soap as complete as possible and (c) isolation of the soap in a condition as free from water and as pure as possible. By this procedure there is incompletely recovered a very impure glycerine of from 5 to strength containing both impurities from the original oils and dissolved salt and lye. The soap resulting contains about of water and salt, free caustic and unsaponified fat, depending on the skill with which the operation has been carried out and also the economics of the situation. The dilute glycerine is purified and recovered by intricate processes and when sold, often represents the only net return in th whole soap operation. Often the saponification operation lasts from 4 to 6 days. The soap must generally be dried so as-to be marketable. This is difiicult because of the gelatinous nature of A really dry soap for making special powdered soaps may be dried for a year.

In the conventional spray drying operation, a I

soap which has been saponlfied as completely as possible and from which the glycerine has been removed is brought into a molten or liquid condition by a combination of factors including heat and moisture. It is then sprayed into a zone which is so arranged that most of the water present will escape as steam and be carried away from the soap particles. The water escapes from the small droplets of soap by bursting through the walls thereof. High temperatures necessitating special heating facilities are required by such procedures.

This invention has for an object the provision of a rational process for producing soap and soap compositions which can be carried out in an economical manner. Another object is to overcome the difficulties of the prior art procedures. A further object is to provide a novel process for making soaps which is applicable to any natural glyceride. A further object is to provide a process for making soap in which the glycerine may be recovered in a substantially anhydrous and concentrated condition. A further object is to furnish a process for making hard soap from oils which have hitherto yielded soft soap. A still further object is to provide a low temperature process for making soap. Another object is to furnish a process for making hard potash soaps. Another object is to furnish a process for making high melting-point wax-like material. Another object is to furnish a process for making lighter colored and more brilliant soaps than formerly possible from a given grade of oil or fat. A further object is to furnish a process for a soap containing a new superfatting agent. A further object is to provide a refined fatty acid monoester from a natural glyceride which can be easily, quickly, and completely saponified to form either a pure dry soap or modified at will. Yet another object is to control the water content of dried soaps within narrow limits. A related object is to prepare particles of soap which have minute pores and do not dust readily. A further object is to provide a process amenable to continuous operation. A still further object is to furnish a process for a new composition of matter consisting of dry crystalline sodium and/or potassium salts of mixed natural fatty acids.

Many efforts have been made to simplify and rationalize the usual procedures. The merely simplified methods so far result in a poor quality of soap. Some of the better methods are sciensoda or potash. The free fatty acid is then neutralized with soda to produce a soap. In one process this involves producing a lime soap which is double decomposed with soda to form a soda soap, All these processes have been in existence for many years, but can only compete under very specialized conditions against the usual saponiflcation procedure first described above.

It has now been found that the above disadvantages can be obviated, the above objects attained and that natural fats can be refin d and made into soaps by first subjecting the dried fat to an alcoholysis with a volatile monohydric aliphatic alcohol of 1 to 4 carbon atoms using caustic soda or its equivalent as a catalyst plus enough alkali to neutralize any present acidity, separating the glycerine by its difference in specific gravity after decomposition with acid of soaps if present, washing with water. mixing the monohydric esters with a saponifying quantity of alkali and completing the reaction and separation of the monohydric alcohol under controlled contions.

To obtain all the benefits of the invention, it is desirable to use all the novel steps herein described. However, some of the benefits are obtainable by using only one or two steps of the complete invention. The invention will first be exemplified in one of its mor complete aspects by a typical procedure with a vegetable glyceride. Coconut oil, which in its usual commercial state, contains a certain amount of water, free fatty acids, mucilaginous matter, protein, coloring matter and sugars, is first selected. The water which will separate by gravity when the oil is in the liquid state is removed. If the oil still contains more than about 1% of water it is then dried by one of the well known means e. g. direct heating of the oil, to less than 1% water content. The free acidity and ester value is determined by the usual method. The oil is heated to a moderate temperature e. g. 25 C. to 100 C. more or less depending on the time the apparatus can be occupied. If a closed system or a reflux is used the temperature and consequently speed of the reaction may be increased. There is then mixed into the oil a substantially water-free solution of commercial anhydrous methanol containing a small amount of caustic soda or potash. The total amount of the methanol used in a one step process preferably should be about 1.6 equivalents of that required for ester interchange. The amount of caustic alkali used in this case should be about 25% greater than that calculated as requisite for neutralization of the free fatty acid content of the oil. In general amounts of caustic alkali in excess of that necessary to maintain alkalinity to Clayton yellow should be avoided. Upon the addition and admixture of this methanol solution the batch should test alkaline to Clayton yellow and continue to do so. If it does not more alkali must be added preferably in methanol solution to maintain this degree of alating power than the acids of the slycerides treated, such as acetic acid is added and mixed in until the formed soap has all been decomposed. Now upon standing the glycerine rapidly separates carrying down with it most of the impurities of the original oil. The fatty acid thus set free remains with the newly formed ester. The conversion of the glyceride to methyl ester is about 98% complete. The lower layer of nearly kalinity. If the acidity of the oil being subjected anhydrous glycerine which is first developed or formed consists of at least about of the glycerine content of the original oil and will contain a small amount of. methanol as well as color and impurities from the crude oil. The glycerine because of its high degree of purity may be used directly in man chemical processes, for example, in the manufacture of glyptal resins. The glycerine and methanol, still retained in the formed esters can be removed by two or three washes with a small amount of water each time. After settling, the wash can be drawn off each time from the bottom. This operation also purifies and lightens the color of the esters. The washing may be eliminated if the esters are to be distilled in accordance with the following procedure.

The oily layer formed consisting of the methyl ester of the coconut oil acids is now fractionally distilled. With the heating up of the oil the small content of fatty acids is rendered noncorrosive. The monoesters distill on an average of 30 to 50 lower than the free acids and can be readily separated therefrom. The distillation of the esters is much simpler than the distillation of fatty acids and has many advantages. The distillation may be effectively conducted under reduced pressure, e. g. 3 min. pressure and with lbs. of steam in the heating coils, first the Ca and then the C10 methyl ester is driven or topped off through a packed column e. g. filled with Raschig rings. The residue in the still consisting of methyl esters of C12, C14, C18 and saturated and unsaturated Cm acids can be drawn off and worked up to soap, or can be further separated by distillation or hydrogenated and separated by crystallization and other known processes.

To make substantially anhydrous soaps, there is added to the mixed monoalkyl esters, e. g. methyl esters which are preferably still warm, a solution and/or suspension of the equivalent quantity of caustic soda or potash in a commercially anhydrous alcohol, e. g. methyl alcohol. This should be mixed in quickly so that it is uniformly admixed before the mass thickens due to soap formation. This mixture may be made into soap flakes by one of the usual procedures and allowed to stand until the neutral soap is formed and most of the evolved methyl alcohol dissipated by evaporation, or the still fluid that is, unreacted, mixture is sprayed into the top of a tower in which there is a current of hot air, and recovered at the bottom as neutral soap powder. The alcohol can be recovered if desired and reused. By using very finely ground or dispersed caustic alkali and suitable mixing device, all or nearly all of the alcohol solvent for the saponifying alkali can be dispensed with especially if some alcohol is added to the esters previous to adding the caustic. The soap so produced by the process just described is an anhydrous pure alkali salt of mixed natural fatty acids. It is crystalline in nature and much harder, brighter, more transparent, and of higher melting point than soaps -made by any of th known processes from the same materials and is apparently a new product. It is also more stable. This is probably because no incipient rancidity has been caused by excessive or prolonged heating as in the usual soap processes.

The processes just described might be outlined as follows: A natural glyceride is first reacted with a substantially anhydrous alcohol, preferably a lower saturated volatile, aliphatic primary alcohol, e. g. methyl or ethyl alcohol in small excess in the presence of a small amount of a dry alkali metal hydroxide above that necessary to neutralize the acidity of the glyceride, any formed soaps are decomposed with an acid such as acetic or hydrochloric acid, the resulting alkyl esters are separated from the glycerine and then subjected to fractional distillation to remove the lower boiling esters; the mixture of higher esters is then reacted with an alkali metal hydroxide, preferably in the substantial absence of water to form soaps.

The amount of alcohol required for the liberation of the glycerine as will be apparent from the above description may be varied somewhat. Furthermore, the amount can be reduced substantially by working in steps. For instance, if the theoretical quantity of methyl alcohol is used for the alcoholysis of a previously refined oil, the conversion will be about 80%. The glycerine can then be removed and more alcohol and catalyst added. If the alcohol is added in small'portions, e. g. in three or four substantially equal portions, the amount required can be reduced, for instance, from one and six tenths times theory to one and one tenth times theory. With a previously refined dry neutral oil the first addition should not be less than four tenths of an equivalent. The preferable amount for the first addition is six tenths of an equivalent.

Amounts of methyl alcohol above 1.75 equivalents tend to prevent the gravity separation of the glycerine thus adding useless expense to the separation. Also the more alcohol used the more goes into the glycerine layer. Amounts of alcohol from 1.10 to 1.75 equivalents represent a practical range. If a previously refined neutral oil is used the amount of alkali required is only that necessary to maintain lkalinity to Clayton yellow during the alcoholysis. With anhydrous caustic soda this is 0.1 to 0.5% by weight based on the oil. .It should be added as a solution in the alcoholysis alcohol. Any alkali metal compound or mixture of such compounds that will give the equivalent alkalinity can be used, e. g. sodium or potassium methylate. At ordinary temperatures and with dry neutral materials the glycerine separates almost immediately. Higher temperatures increase the speed of this reaction so that it is practicable to run it in a continuous process with continuous feed of proportioned ingredients and separation of glycerine and washes by continuous centrifuging.

When the step-wise alcoholysis or ester interchange is applied to unrefined oil, certain precautions must be observed. In this case the first addition of esterifi'ing alcohol and catalyst should be somewhat nearer the theoretical equivalency than when working with refined oil. The dissolved caustic of this addition must be enough to neutralize all free acidity plus a catalytic excess, so as to show continued alkalinity to Clayton yellow. After the reaction and decomposition of the formed soap by the addition of acid and separation of the first portion of glycerine another portion of alcohol containing catalyst in solution is added and the next portion of glycerine separated.

Various kinds of acids may be used for decom-- posing the soap or soaps formed during the alcoholysis step. In general, a mild acid having an .be economically obtained in a substantially waterfree or anhydrous form are preferred. Suitable acids include formic, acetic, propionic, hydrochloric, sulfuric, sulfamic, phosphoric, etc. acids. In general, the mineral acids should be used in diluted condition.

If a concentrated caustic soda solution, e. g. 50% strength is used, as the saponifying agent, it preferably is emulsified with themethyl esters to a homogeneous emulsion before the reaction causes much thickening. The emulsion may be treated as described above, and will produce a neutral soap containing about 12% water which is the usual amount in fine soaps. However, if more concentrated solutions of caustic alkali are used, soaps with a lower Water content may be obtained. If sodium carbonate is used, high heating Or autoclaving will be necessary to effect the reaction. If a deficiency of saponifying alkali is employed the finished soap will still be neutral and will contain a valuable superfatting material that is the mono ester or esters of the fatty acids from the glycerides with the alcohol used.

A somewhat narrower but important use of the invention is involved in making valuable products including soaps, from cotton seed and similar unsatrrated oils. Refined oils when employed result in a saving of chemicals but crude oils can be used'by adding extra alkali to compensate for the free acids as explained above. The ester value and acidity are determined and 1.6 equivalents of methyl alcohol containing about 25% of caustic soda in excess of that needed to neutralize free acids is admixed. The mixture is warmed to 1 about 25 to C. and the formed soaps decomposed With acetic acid, the glycerine is drawn off and the oil washed free of glycerine and alcohol. The methyl esters of the cotton seed oil acids are treated with saponifying agent to produce an anhydrous soap. The soap is found to be hard like the ordinary soap made from saturated fats and has the above described properties.

The mixed esters of the unsaturated acids, e. g. the methyl esters from the cotton seed oil may be hydrogenated and distilled to form fractions of nearl pure methyl palmitate and methyl stearate. If the methyl stearate, for instance, is converted into an anhydrous soap as sodium stearate, there is obtained a crystalline waxy material melting at about 260 C. It is useful as an in gredient of waxy coatings, for instance, of use in coating paper, producing paper from which later printing ink can be easily removed.

The use of a spraying device for completing the manufacti're of soap from the monohydric alcoholic esters of fatty acids presents a number of new aspects. The actual conversion from a mixture of ester and alkali to soap can be delayed, say by temperature control, until the moment when the spray forms. As this conversion is exothermic and as the mixture or emulsion of ester and alkali plus the controlled quantity of material still containing the small amount of water desired in the finished product. The form of the product is different from any form previously made though it can be made to simulate previous forms. A main characteristic of the novel product is its porous, sponge-like structure and dust free nature. Another characteristic is light gravity. This is in part due to the fact that the material is produced by the evolution of alcohol or alcohol plus water rather than water.

An important aspect of the invention is that it can be carried out continuously. This can be done without the use of high temperatures and pressures or corrosive conditions. The-glycerine and wash waters can be separated by continuous centrifuges. The monohydric alcohol ester of fatty acids, as it issues-from the centrifuge, can be mixed with a proportioned amount of caustic alkali continuously, for instance with the help of a homogenizer. and the reaction can then be made to occur almost instantaneously by the application of a very little heat as the product is being sprayed or drum flaked. The invention will be further illustrated, but is not intended to be limited by the following examples:

Example I The amount of 99.8% purity methanol required for equivalency to the glycerine is The first treatment of the oil is with 0.7 of an equivalent or 0.7 of 145.3 lbs.' -101.7 lbs. methanol. In this methanol is dissolved 1.25x5.4=6 lbs. 12 ozs. of 92% NaOH. To the dried cocoanut oil now at a temperature of about 80 C., is 55 added under stirring this solution of 6 lbs. 12 ozs. caustic soda in 101.7 lbs. methanol. The tem- =5.4 lbs.

I perature is held up so as to increase the solubility of the impurities in the glycerine. On testing the batch is found to be alkaline to so Clayton yellow, After fifteen minutes, the agitator is started again and 10 lbs. 5 ozs. glacial acetic acid added. The agitator is stopped and at the end of one half hour the glycerine layer which has meanwhile settled out is drawn off.

For the second treatment 0.2 equivalent of such substantially anhydrous methanol or 29 lbs. is used containing 2 lbs. caustic soda. This is mixed in for a few minutes and allowed to stand. On testing the batch is found to be alkaline to Clay- 70 ton yellow. At the end of 20 minutes the glycerine layer is drawn off and another treatment is made with 29 lbs. methanol containing 2 lbs. caustic in solution. Upon'analyzing, it is now found that the glycerine layers when combined 76 amount to about 169 lbs. of this following composition: I

Glycerine 128 lbs. 75.7% Methanol 12lbs.- 7.1% Esters and soaps 5lbs.-- 3.0% Sodium acetate 121bs.- 7.1% Water, NaOH and impurities--- 12lbs. 7.1%

169 lbs. 100.0%

The oil or ester layer is found to amount to about 1006 lbs. containing:

Methyl esters 941 lbs.' 93.5%

Methanol 6 .9 lbs. .7 Glycerides 29 lbs. 2.9% Free fatty acids 25.5 lbs. 2.5% Sodium acetate 1.5 lbs. .2% Glycerine 1.7 lbs. .2

1005.6 lbs. 100.0%

Pounds Methyl esters Glycerides 995.5 Free fattyacids Caustic soda 186 Water 124 Methanol free and in combination 148 This homogenous liquid is now worked in a mixer while the soap reaction occurs. The temperature rises spontaneously and a portion of the alcohol vaporizes off along with a portion of the water. The material is now formed into soap cake by the usual methods. The cakes of soap totalling about 1150 lbs. contain about 7% water and 3% methanol and are completely saponified that is less than 0.1% free alkali content.

Example II Glycerine 134 lbs.- 67% Methanol 40 lbs.- 20% Esters and soap. 24.51bs. 12.3% NaOH 1.5lbs. .7%

200.0 lbs. 100.0%

The oil or ester layer amounts to 1045 lbs. and analyzes:

Methyl esters 971lbs.- 92.9% Methanol 40 lbs. 3.8% Glycerides 30 lbs. 2.9 Glycerine 4 lbs. .4%

1045 lbs. 100.0%

, Pounds Methyl esters 97 Glycerides 30 This oil is submitted to fractional distillation to top off or remove the methanol and the lower esters that is the Ca, Ca, and part of C10 esters. The mixture, remaining in the still amounting to 830 lbs. is found by analysis to require;140 lbs. NaOH to saponify it. Two hundred-forty pounds of caustic soda solution containing 140 lbs. NaOH and being at a temperature of about 60 C. is mixed with the 830 lbs. of topped esters. The topped esters are at a temperature of about 70 C. when introduced to the mixing device. The mixing is done by feeding continuously the two materials by proportioning pumps to an homogenizer. The outlet of the homogenizer feeds by a short steam jacketed connection, the spraying device of a spray tower similar to that commonly used for spray drying soap. However, the temperature of the carrier gases in the spray tower are only about one-half that usually employed. This is because there is heat liberated from the saponification reaction. The temperatures of these carrier gases is controlled so that the finished product is completely saponified and analyzes about water and only traces of'methanol. The product is porous, sponge-like discrete particles free from dust and has an apparent density such that it easily dissipates in water.

Example III One thousand pounds of refined Cochin type from a solution of potassium hydroxide by adding a light petroleum fraction e. g. kerosene and distilling. The finely dispersed potassium hydroxide obtained is mixed with 830 lbs. of topped methyl esters. The temperature of the methyl esters at the start is about 20 C. As soon as the mixture is homogeneous, it is worked in. a jacketed mixer with a small amount of heat in the jacket. The reaction occurs and the material passes through a plastic stage to a powdery one. There is obtained an anhydrous potassium soap which can be ground to as fine a powder as desired. This powder is not hydroscoplc and is suitable for dispensing from a can with a perforated top, say for shaving soap.

Example IV Seven hundred and fifty pounds of refined cotton seed oil and 250 lbs. of a neutral hardened fat whose fatty acids have a titer of about 55 C. are melted together and brought to a. temperature of 80 C. The composition is:

Per cent Glyceride, unsaturated Cm, one double bond- 30 Glyceride, unsaturated C18, two double bond 33 Glyceride, saturated 37 The ester value is such that theoretically 1,000 lbs. require 111 lbs. pure methanol for alcoholysis. 1.2 equivalents methanol, therefore, equals about 133 lbs. In 133 lbs. of commercial anhydrous methanol is dissolved five pounds of anhydrous 96% caustic soda. One-half this solution is stirred into the warm oil for five minutes and the agitation stopped. During this admixture the batch is first cloudy and then clears up. As the reaction proceeds, it again becomes cloudy due to separated glycerine. At this stage a sample is taken and tested in a Gerber milk testing centrifuge. If the glycerine layer amounts to of the total volume, the reaction mass is ready for centrifuging. If not, more time is needed for the reaction to occur. When reacted, the batch is run through a centrifuge and separated into two portions, one of about 1009*lbs. and another of about 60 lbs. which contains the separated glycerine. To the 1009 lbs. is added the second half of the methanol solution and the procedure again followed as just detailed. The combined portions of separated glycerine amount to about 129 lbs. and contain:

Glycerine 102 lbs.- 79.0% Methanol -1- 18 lbs.-- 14.0% Esters and soaps '7 lbs. 5.4% Causticsoda 2 lbs.- 1.6%

129 lbs. ,100.0%

The oil or ester layer amounts to about 1009 lbs. and contains:

Methyl esters 981 lbs.- 97.2%

From the composition it is calculated the 1009 lbs. of methyl esters would require 140 lbs. NaOH to saponify them. They are charged into a jacketed mixer with tight cover of the Werner and Pfleiderer type. Thereis also charged in 150 lbs. commercial anhydrous methanol and when this is uniformly intermixed there is quickly admixed 145 lbs. finely dispersed caustic soda containing 140 lbs. NaOI-I. There is now admixed 15 lbs. of finely ground sodium salt of trimethylamine tricarboxylic acid, 60% purity. The agitation is run with a closed cover until the mass has become discrete. Heat and vacuum are then turned on with slow agitation until 220 lbs. of methanol have been evaporated off. The finished product is a bulky powder of marked detergent properties even in hard water. It is anhydrous and nonhygroscopic and remarkably stable. The combined fatty acids contained in it are over unsaturated Cm and of them over half have double unsaturation. A similar product is made by omitting the addition of the sodium salt of trimethylamine tricarboxyli'c acid and making up the finished material to contain 10 to 25% of sodium phosphates or poly phosphates. These phosphates should not introduce more than 5% water from their water of crystallization.

Emample V Bleached, dried and filtered neutral soap stock is brought to a uniform molten or liquid condition and analyzed. It is found to have an average molecular weight of 863 which means that 1,000 lbs. of it theoretically requires 111 lbs. of pure methanol for alcoholysis or 139 lbs. pure caustic soda for saponiflcation. An apparatus is provided which is special as to certain features.

It may be made of iron. For a production of 8,000 lbs. per hour of soap this apparatus ineludes:

A. A continuous mixer of about 20 gals. ca-- pacity so that average hold up of material passing through it is one minute.

B. A continuous gravity separator of about 350 gals. capacity so that average time of passage is about 20 minutes.

C. Another mixer but of about 1'75 gals. capacity so that average passage time is minutes.

D. A continuous centrifuge planned for removing continuously the heavier component of about 5%.

E. A continuous mixer and homogenizer for oil and caustic soda solution. Time of passage, brief.

F. A spray tower.

A solution of caustic soda in methanol is made containing 2 /270 caustic soda. The melted fat is maintained at a temperature or about 80 C. and is fed continuously to mixer A at the rate of 8,000 lbs. per hour. Simultaneously, the methanol solution is fed to the same mixture in the proportion of 7.9 lbs. methanol solution to 100 lbs. oil by means of proportioning pumps. The effluent from mixer A flows continuously to separator B which may be lagged to prevent loss of heat. About 6% is continuously drawn from the bottom of a glycerine fraction. The continuous overflow goes to mixer C to which is also fed continuously a stream of the above methanol solution in the proportion of 5.6 lbs. methanol solution to 100 lbs. of oil. From this mixer a continuous stream is red to the centrifuge D. The continuous stream of oil at about temperature 70 C. from D is fed to mixer E and at the same time by a proportioning pump is fed to E a stream of warm 60% caustic soda in the ratio of 23 lbs. ofthissolutionto 100 lbs. of the oil. The discharge from this machine is by a steam jacketed pipe direct to the spray nozzle of tower F. The time of flow in this last step is such that the mixture is just beginning to gelatinize evidencing the initiation of the saponification, as it leaves the spray nozzle. As the material is sprayed and falls down the tower, the combined alcohol evolves and is carried away from the soap by the hot carrier gases. These gases are not hot enough to dry the last five per cent of water from the soap.

The range of glycerides available for producing soap directly by this process is greater than that available for the old processes because harder soaps can be made from liquid glycerides. In place of the specific glycerides described above may be substituted other animal and vegetable fats and oils which have been used for the production of soap. As examples of additional suitable materials, mention is made of olive oil, palm oil, sardine oil, castor oil, whale oil, linseed oil, stearin, tallow, cocoa butter, etc.

The preparation of the esters of the fatty acids preparatory to making soap from them as taught herein is not limited to the specific alcohols above named, but other alcohols may be used. Thus, saturated aliphatic alcohols or alkanols having from 1 to 4: carbon atoms have utility. The preferred alcohols are saturated aliphatic monohydric alcohols boiling below about 100 C. and especially below about 85 C. As examples of additional suitable alcohols, mention is made of propanol, isopropanol and the butanols. Of these,

those which are water miscible and most volatile are preferred. An amount of alcohol above 1.75 equivalents or use of an alcohol with great intersolubility powers with glycerine such as methylpropylcarbinol will tend to prevent or prevent the glycerine from settling to the bottom and separating as an easily removable phase.

One important embodiment of the invention I is concerned with the use of caustic potash as the saponifying agent in above procedures, whereby hard potash soaps are formed. These soaps are believed to be new mixtures and have greater utility in the arts.

The invention has a number of decided advantages, among which are:

(1) The starting material may be any glyceride,

(2) The glycerine may be removed me. very pure and highly concentrated form,

(3) There are very small amounts of byproducts formed, for instance, the small amount of lower alcohols does not require recovery to make the process economical.

(4) The catalysts used are very cheap and do not have to be recovered,

(5) The lower alkyl esters of the fatty acids from the glycerides readily mix with the saponifying agent and allow the saponification to proceed rapidly,

(6) The reaction starts and completes at low temperatures,

(7) The soaps are not subjected to prolonged or excessive temperatures at any stage,

(8) The initial and final products are noncorrosive to metals,

(9) Large amounts of caustic soda do not have to be recovered,

(10) Glycerides which were hitherto not utilized for making soaps because they yielded soft soaps by the conventional method can be converted by this process into hard soaps without the necessity of first hydrogenating.

It is possible to produce soaps difierent from those of the prior art. For example, they can be made lighter in color, non-irritating, and containing a neutral superfatting agent. They may be obtained in a pure anhydrous form having less than of electrolyte content. However, various amounts of water may be contained in the final products.

Fats and inorganic or organic diluents, as soap builders and cake formers, solubility modifying agents, preservatives, bleaching agents, may be compounded with the soaps, as lanolin, stearyl alcohol, methyl stearate, sodium carbonate, sodium silicate, sodium phosphate, sodium pyrophosphate, alkali metal salts of polybasic phosphorous acids, e. g. sodium polyphosphate, polycarboxylic tertiary amines, including those of U. S. P. 2,240,957, sodium perborate, cyclohexanone, glyceryl acetals, e. g. methyl cyclohexanone glyceryl acetal, cyclohexanone glyceryl acetals, etc. glue, glyceryl monooleate, glyceryl monostearate, bentonite, perfume, etc.

The anhydrous pure soap which consists of a mixture of salts of higher fatty acids have great utility and may be substituted in a great many arts in the same way that-soap and the newer soap-substitutes have been used.

The properties of these soaps described above make them suitable for use in a large number of processes. The following uses are suggested as being indicative of the manner in which the products may be employed: scouring raw wool, fulling, sizing, desizing, impregnating, bleaching, mordanting, lime soap dispersing, mercerizing,

ming, kier boiling, felting, oiling and lubricating,

dyeing cellulose acetate fibers with insoluble dyes, dyeing of leather, dye printing pastesrpastes of dyes or dye components, preparation of lakes, preparation of inorganic pigments, emulsiflcation and dispersion, treatment of oil wells, air foam and chemical foam fire extinguishers, cooking wood pulp, radiator cleaners, stripping? dyeing in neutral, or alkaline dye baths, dyeing of animal fibers with vat dyes, cleansing agents, fat liquoring, washing paper mill felts, improving absorbency of paper products, household dye preparations, metal cleaning, removal of fibrous layers from surfaces, shampoos, insecticides and agricultural sprays, scouring rayon, flotation, breaking petroleum emulsions, food preparations, creping assistant, flooding oil bearing sands, ceramic assistant, polishing, abrasive and bufling compositions, dentrifices, agents to prevent rubber and other plastics from sticking tomolds, in adhesives such as starch, glue and casein and in compositions containing degraded proteins, washing of discharge prints, softening finishing and reducing static charges on textile materials especially from cellulose derivatives such as cellulose acetate. I

Thus, the herein described sodium and potassium soaps may be substituted in equal amounts for the alkyl betaines in Examples 16, 18 to 31, inclusive, 34, 36 to 53 inclusive, 55 to 59 inclusive, and 61 to 66 inclusive, of French Patent No. 849,393. The soaps may be mixed with soaps produced by other processes or with soap substitutes such as alkyl naphthalene sulfonic acids, Turkey red oil, higher aliphatic alcohol sulfates, higher alkyl betaines both of the C and N type, mineral oil sulfonates, etc. 7

As many apparently widely different embodiments of this invention may be made without departing from the spirit and scope thereof, it is to be understood that we do not limit ourselves to the specific embodiments herein except as defined by the appended claims.

This application is a c'ontinuation-in-part of application Serial No. 268,820, filed April 19, 1939,'

now Patent No. 2,271,619.

We claim:

l. The process which comprises reacting a crude glyceride with an alkanol of not more than 4 carbon atoms under substantially anhydrous conditions in the presence of sufilcient alkali metal base to neutralize the free acids in said glyceride and to maintain the solution alkaline to Clayton yellow, adding an acid in suflicient amount to decompose the soaps formed, separating the glycerine and recovering monoalkyl esters of the fatty acids contained in said glycerides.

2. The process which comprises reacting a crude glyceride with an alkanol of not more than 4 carbon atoms under substantially anhydrous conditions in the presence of sufhcient alkali metal base to neutralize the freeacids in said glyceride and to maintain the solution alkaline to Clayton yellow, adding an acid to the mixture of alkyl esters in suflicient amount to decompose the soaps formed, separating the glycerine and recovering monoalkyl esters of the fatty acids contained in said glycerides and saponifying said esters.

3. The process which comprises reacting a crude glyceride with an alkanol of not more than 4 carbon atoms in the liquid phase at moderate temperatures under substantially anhydrous conditions in the presence of suflicient alkali metal 15 base to neutralize the free acids in said glyceride crude glyceride with an alkanol of not more than 4 carbon atoms in the liquid phase under substantially anhydrous conditions, in the presence of sufllcient alkali metal hydroxide to neutralize the free acids in said glyceride and to maintain the solution alkaline to Clayton yellow, adding an acid in sllfilcient amount to decompose the soaps formed and separating the alkyl esters from the glycerine, distilling said esters and saponifying at least one fraction of latter.

5. The process which comprises reacting a crude glyceride with an alkanol of not more than 4 carbon atoms under substantiallyanhydrous conditions, in the presence of suflicient alkali metal hydroxide to neutralize the free acids .in said glyceride and to maintain the solution alkaline to Clayton yellow, adding an acid in sufficient amount to decompose the soaps formed; the amount of alkanol employed being not more than 1.75 equivalents of the glyceride.

6. The process which comprises admixing alkyl esters of higher fatty acids and an alkanol of 1 to 4 carbon atoms-in the liquid state with a solution of caustic soda of at least 40% strength in an amount sufficient to saponify said esters, and spray drying the resulting solution.

7. The process which comprises admixing alkyl esters of higher fatty acids and an alkanol of 1 to 4 carbon atoms in the liquid state, with an aqueous solution of caustic soda of at least 40% strength in an amount suiiicient to saponify the said esters, and spraying the resulting solution into a gaseous medium maintained at a temperature sufilcient to vaporize the said alkanol.

8. A continuou process which comprises admixing alkyl esters of higher fatty acids wherein the alkyl groups contain from 1 to 4 carbon atoms in the liquid state with an aqueous solution of caustic alkali of at least 50% strength and spraying the same into a chamber containing a gaseous medium at a temperature sufiicient to carry oil the vapor phase of the alcohol set free.

. 9. A continuous process which comprises admixing alkyl esters of higher fatty acids wherein the alkyl groups contain from 1 to 4 carbon atoms in the liquid state with an aqueous solution of caustic alkali of at least 50% strength, heating said mixture to a temperature whereby saponiflcation is initiated and spraying the same into a chamber containing a gaseous medium at a temperature suiiicient to carry off the vapor phase of the alcohol set free.

10. A continuous process which comprises admixing alkyl esters of higher fatty acids wherein the alkyl groups contain from 1 to 4 carbon atoms in the liquid state with an aqueous solution of caustic alkali of at least 50% strength, heating said mixture to a temperature whereby saponification is initiated and spraying the same into a chamber containing a gaseous medium at a temperature sufficient to carry off the vapor phase of the alcohol set free, but insuflicent to vaporize all the water.

11. A continuous process which comprises admixing alkyl esters of higher fatty acid wherein the alkyl groups contain from 1 to 4 carbon atoms in the liquid state with an aqueou solution of caustic alkali of at least 50% strength heating said mixture to a temperature whereby saponification is initiated and spraying the same into a chamber containing a gaseous medium at. a temperature sufilcient to carry off the vapor phase of the alcohol set free but insuflicient to completely dry any substantial amount of the soap.

12. The process which comprises reacting a crude glyceride with successive portions of an alkanol of not more than 4 carbon atom in the liquid phase under substantially anhydrous conditions, in the presence of sufficient alkali metal hydroxide to neutralize the free acids in said glyceride and to maintain the solution alkaline to Clayton yellow, the first portion being at least 0.4 of a chemical equivalent and not more than 1375 equivalents, adding after the first addition an acid in sufficient amount to decompose the soap formed, settling after each admixture and drawing of! each resulting glycerine layer until the total alcohol added is equal to the chemical equivalent of the glyceride plus the alcohol contained in the glycerine layers, the whole process being carried out at moderate temperatures.

13. A process as set forth in claim 2 wherein the esters are heated prior to the addition of said acid.

14. The process which comprises admixing alkyl esters of higher fatty acids and an alkanol or 1 to 4 carbon atoms in the liquid state, with a small amount of an alkanol of 1 to 4 carbon atoms and saponifying the mixture with a dispersion of a solid alkali metal hydroxide.

155. The process of claim 12 wherein the reaction and steps are carried out in a continuous manner.

GEORGE BURT BRADSHAW. WALTER C. MEULY. 

